converting from 9v for push button

Forum 2005-2010 (read only) Hardware Interfacing
1

Ok,
this is really straight forward, but I want to double check. I'm in the process of making a shield for a project and I for the sake of routing the traces I need to use the voltage from VIn (which is running @ 9V) and I want to use this to run 6 push-button inputs.

I assume that I need to convert the 9V down to 5V for the button, but I'm not sure what resistor to use to do this as I don't know how many ma the button is drawing.

thanks for any help

Nick

2

Don't connect the push buttons to +ve at all. Connect them between the arduino input and ground. Then enable the internal pull up resistors in software.

P.S. A push button draws an infinite number of mA, it's a short circuit. :slight_smile: